<!doctype html>
<html lang="en">
<head>
  <link rel="stylesheet" href="https://cdn.jsdelivr.net/gh/openlayers/openlayers.github.io@master/en/v6.5.0/css/ol.css" type="text/css">
  <style>
      html, body, .map {
          height: 100%;
          width: 100%;
          padding: 0;
          margin: 0;
          overflow: hidden;
      }
  </style>
  <script src="https://cdn.jsdelivr.net/gh/openlayers/openlayers.github.io@master/en/v6.5.0/build/ol.js"></script>
  <title>OpenLayers example</title>
</head>
<body>
<div id="map" class="map"></div>
<script type="text/javascript">
    var source = new ol.source.OSM();
    var base = new ol.layer.Tile({
        source: source
    });
    var base1 = new ol.layer.Tile({
        source: source
    })
    var map = new ol.Map({
        target: 'map',
        layers: [
            base, base1
        ],
        view: new ol.View({
            center: ol.proj.fromLonLat([103.572, 36.897]),
            zoom: 4
        })
    });
</script>
</body>
</html>